1. Field of the Invention
The present invention relates to an optical measuring apparatus for measuring physicochemical properties of specimen utilizing the optical echo which is a nonlinear optical phenomenon.
2. Related Background Art
There are various laser scanning microscopes with laser beam source conventionally known as the technology for measuring a specimen in high definition. As a typical example, a confocal laser scanning microscope has the structure for measurement in which a spot beam is guided to irradiate a specimen located at a focal position of illumination system and in which light from the specimen is focused on a pin hole then to be detected by a photo detector. Since the depth of focus is very shallow for image obtained in measurement by the confocal laser scanning microscope, the microscope has a superior advantage that an infinite depth of focus can be obtained by so-called sectioning effect in scanning in the direction of optical axis.
Meanwhile, there is no great qualitative difference made between information of specimen obtained in measurement with conventional laser scanning microscopes represented by such a confocal laser scanning microscope and information obtained from image through conventional optical microscopes using no laser beam source as more generally known. In other words, it can be said that no technical (qualitative) great difference exists in measuring structural or configurational characteristics of specimen between the laser scanning microscopes and the more general optical microscopes using no laser light. Further, the laser scanning microscopes have no function to measure the general properties of specimen including not only the external properties such as the structure and the configuration but also the physicochemical properties such as microscopic dynamics (in other words, inherent properties).
It is, however, very important for example in medical field to measure the physicochemical properties of specimen such in addition to the external properties of specimen extirpated from organism. The conventional laser scanning microscopes were not provided with such a function to meet the demand. The demand is not only in medical field but also in other diverse fields, for measuring apparatus which permit the measurement of physicochemical properties of specimen.